Well drilling apparatus



Dec. 7, 1943. R. oGARRlo VWELL DRILLING APPARATUS- Filed Feb. 27, 1942 PVP/ RODOLFO OGRIO I N VENTOR HIS yPatentedDec.7.,'1943i Y WELL' DBIILING APPARATUS l nodouo ogarrio, New York, N. y., manor to 'rho Texas Company, New York, N. Y., a corporation ofl Delaware application February zr, iaraseriai No. 432,510 A z claims. (ci. c55-4) This invention relatesto the drilling of wells and more particularly 'to a method and an apparatus for drilling oil by -rotating a cutting tool against the formation by means of a turbine or motor disposed directly above the cutting tool and supplied withI a fluid from the surface through a non-rotatable pipe string extendingfrom a pump at the surface to the motor or tur-v bine with the well bore. The principal object of the invention is to provide a method and an apparatus through the use of which a good mud cake will be built up on the Walls of the well bore.

In the rotary method of drilling a well a cutting tool or bit secured to the lower end of a 'pipe string is adapted to cutl or bore into the formation when the pipe string is rotated from the surface. In this method, fluidsuch as drilling mud is -pumped Adownwardly through the rotating drill pipe stringl from which itY passes outwardly through openings in the bit. The mud picks up the cuttings and carries them in suspension upwardly to the surface between the drill pipe string and the walls of the bore. The drilling mud fluid serves another important purpose and this is to deposit a layer of mud.' usually termed a mud cake, on the walls of the bore. This mud cake serves to seal the formations traversely by the well bore and thus to prevent or 'retard water infiltration. Ther mud cake also tends to mainain the walls, or, in other words, to prevent crumbling and sloughing of the formations.

In another method of Well drilling, a fluid, which may bea drilling mud, ispumpeddownwardly through a non-rotating .tubing or pipe string to a motor such as a turbine disposed at the lower end ofthe string and attached directly to a cutting tool or drilling bit. The mud fluid being pumped downwardly under l pressure through. the turbine causes rotation of the ^drill ing bit and the cuttings are picked up and carried in suspension `upwardly to the surface through the space between the pipe strin-g and the walls of the bore in a manner similar to that previously described. This method of well drilling is described in several U. S. Letters Patent, for example, the patent to Capeliuschnicoi, No. 1,681,094, granted August 14, 1928. Ithas been found to-be very dimcult, if not impossible,v to

'As stated hereinbefore, it is the' principal purpose of this invention to provide a method and means through the use of which a uniform mud cake can be obtained on all ofthe well bore surface.

In accordance with the invention, means is providedon the exterior of thenon-rotatable pipe string for imparting va rotaryorspiral movement to the mud during its travel from the bit upwardly to the surface. By this rotary motion a certain centrifugal force is imparted to the mud and, due to this centrifugal force and also the fact that, due to the swirling movement of the mud all of the surface of the well bore will be contacted by the mud, an efficient mud cake is provided. Were it not for this rotary or spiral movement of the mud, the uid in passing upwardly would, as has been explained, seek the mostdirect path and channeling of the walls of the well bore would result. Because of this channelling action, parts of the formations might be loosened so as to fall into and plug the Well bore; but, what is probably more important, it would be substantially impossible to secure a mud cake of' good consistency and uniform thickness on the walls of the bore. f,

In carrying out the invention I have provided on the exterior 'surface of the non-rotatable pipe string a iin or flange extending outwardly, substantially radially. The fin or flange is formed in the shape of a spiral or helix and therefore when the mud starts upwardly from the drillingbit a rotary or spiral motion will be 'imparted to the mud, and in prevented while at the s ame time a uniform mud cake will be built up on the walls of the bore.

For a better understanding of the invention reference may be had to the accompanying drawing in which the single ligure discloses a vertical build up a good mud cakel on the walls of a well drilled in this manner, since the mud fluid usually passes straight upwardly through the drilled formations following the most direct path. Channeling of the formations yfrequently occurs. and portions of the softer strata are often washed away thus leaving cavities and an irregular' hole. 65 bine elevation, partly in section, vof a well bore with the drilling apparatus in place.

Referrin-gto the drawing, a well bore I0 is shown asjhaving been. drilled through various formations or strata by means of a cutting toolv or bit I2 adapted to be rotated by means of a uid motor or turbine I4' secured at the lower end of a pipe string I6. A mud pump I8 at the surface adapted to be driven by means of a suitable engine 20 is provided with an in-take pipe or tube 22 extending into a mud sump or pool 24.

'A flexible hose 26 conducts the mud fluid under pressure from the pump I8 to the upper end of the pipe string I6 and the pressure of the mud acting upon the elements, not shown, of the turthis manner channelling will be ll causes rotation of the shaft of the turbine I patentto Verneuil, No. 1,412,430, granted April 11, 1922, may be used. It is also understood that the pipe string I6 will be suspended in the hole Il in any suitable manner sol that additional pipe sections can be added as the string moves downwardly.

; Each section or length of the pipe forming the string i8 is provided around its exterior surface with a iinor flange 28, this flange being formed asaaoao vand thus the cutting toolV I2 in a manner well dang-e' be so wide as to contact the walls of the hole since this would render diilicult the removal y of the pipe string from the hole.'

- patent to Capeliuschnicoif, No. 1,681,094, or the Although the pipe string IB has been described as formed of a plurality of lengths of steel pipe, it is` also contemplated that a iiexible pipe or conduit of rubber or the like can be utilized to conduct the mud fluid to the turbine I4. Such in the shape of a helix or spiral and being attached that the flange 28 bel positioned on the pipe sections in such a manner that when the threaded connections between adjacent sections of pipe are made'u-p the flange will form a substantially continuous spiral.

In operation the mud which passes through the to the pipe in any suitablemanner, as by welding. While it is not-absolutely essential, it is preferred turbine Il will be exhausted either directly from the lower end of the turbine or, if desired, through suitable holes in the drill bit I2 so that it will pick up the cuttings made bythe bit and conduct them in suspension to the surface. Due to the provision of the spiral flange 2l the mud fluid in passing upwardly beyond the upper end of the turbine Il will tend to follow the spiral direction of the flange, as is indicated diagrammatically by the dotted line 30. A swirling movement will .thus be imparted to the mud and the iiuid will thereby be caused to contact all of the surface of the well wall. Assuming 'a rate of mud fluid flow of, say,

400 gallons per minute for 'a well having a depth of around 4000 feet, an appreciable centrifugal force' will be generated in the mud iluid which will cause an increased pressure between the 'mud fluid and the well walls, and the plastering action of the fluid will be considerably amplied. Inthis to and line the walls of the well bore in such a manner as to prevent crumbling of the formations" and water infiltration. Channeling of the forma-v non was, by-the passage of the mud fluid win be' prevented.

'I'he width of the flange 2l may vary somewhat in accordance' with the `-.rate ofl mud now, vthe depth of the hole, etc, :It is not intended that the manner a mud-,cake $2 will be built up to adhere a conduit can obviously consist of one continuous length or of a plurality of lengths suitably connected together. The spiral iin or flange can either be formed integrally with the flexible tube or can be attached to the outer surface by any suitable means as by cement.

' Obviously many other modifications and variations of the invention,'as .hereinbefore set forth, may be made without departing from the spirit and scope thereof, but only such'limitatlons should be imposed as are indicated in the appended claims. y

Iclaim: l. A well drilling'apparatus comprising a cutting tool, a fluid driven motor connected to and wardly to the surface around'said conduit, and

means for imparting a rotaryi motion to said upwardly ilowing fluid comp' g aspiral flange secured to andl coextensive with the exterior of I said conduit, the centrifugal force developed by said rotary'motion causing the mud iiuid to plaster uniformly the walls of the hole.

2. A well drilling apparatus comprising a outting tool, means for rotating said tool against the formation, said means comprising a iiuid driven 'motor connected to and directly above said tool,

a mud pump at the surface, anon-rotatable conduit connecting said niotor and said pump and adapted to conduct mud iiuid under pressure from said pump to said motor, and means for imparting a rotary motion and centrifugal force to the uid returning from the motor to the surface through the annular space between said conduit and the walls of thewell, said means comprising a spiral iin projecting radially from the exterior surface of said conduit andA extending throughout the length of the conduit.

Bonomo oGARmo. 

